A clinical study of thermal monitoring techniques of ultrasound-guided microwave ablation for hepatocellular carcinoma in high-risk locations.

To confirm the safety and effectiveness of the minimally invasive thermal monitor technique on percutaneous ultrasound-guided microwave ablation (MWA) for hepatocellular carcinoma (HCC) in high-risk locations, a total of 189 patients with 226 HCC nodules in high-risk locations were treated with MWA. The real-time temperature of the tissue between the lesion margin and the vital structures was monitored by inserting a 21G thermal monitoring needle. The major indexes of technical success, technique effectiveness, local tumour progression and complications were observed during the follow-up period. Technical success was acquired in all patients. Technique effectiveness was achieved with one session in 119 lesions based on contrast-enhanced ultrasound (CEUS) 3-5 days after treatment. An additional 95 lesions achieved technique effectiveness at the second session. Within the follow-up period of 6-58 months (median 38 months), the 1-, 2-, 3-, and 4-year local tumour progression rate was 11.1%, 18.1%, 19.1%, and 19.9%, respectively. There were no major complications in all the patients except for the common side effects. These results indicate that the thermal monitor technique can be applied to prevent major complications in vulnerable structures and allow percutaneous MWA to achieve satisfactory technique effectiveness in the treatment of HCC in high-risk locations.

Unplanned pregnancy after ultrasound-guided percutaneous microwave ablation of uterine fibroids: A follow-up study.

A follow-up study was performed with 169 women of childbearing age who underwent ultrasound-guided percutaneous microwave ablation (UPMWA) therapy for symptomatic uterine fibroids in the Chinese PLA General Hospital from June 2007 to December 2014. This study aimed to observe the incidence of unplanned pregnancies in these women after UPMWA treatment in order to evaluate its effect on natural conception. Ten unplanned pregnancies in nine women were occurred. Of the nine patients, six did not want the pregnancy and chose for induced abortion to end the pregnancy at an early stage. Three chose to continue with the pregnancy and gave birth to a healthy term infant delivered by cesarean section (of these three patients, two had been previously diagnosed as infertility). None of the patients had any serious obstetric complications. After UPMWA treatment for uterine fibroids, patients may conceive naturally, the impact of the procedure on fertility and pregnancy outcomes is worthy of further prospective study in larger sample.

Long-term effects of ultrasound-guided microwave ablation in the treatment of small renal cell carcinoma / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the long-term efficacy of microwave ablation in the treatment of small renal cell carcinoma (RCC).</p><p><b>METHODS</b>We retrospectively analyzed 140 cases of small cell renal carcinoma (151 lesions with a mean diameter of 2.8±0.8 cm) treated between April, 2006 and October, 2015 with ultrasound-guided microwave ablation with cooled-shaft needle antenna. One microwave ablation antenna was used for tumors less than 2 cm in diameter and 2 antennas were used for larger tumors. The patients received enhanced ultrasound and CT/MRI examinations at 1, 3, and 6 months after the operation and every 6 months thereafter. The overall survival, disease-free survival, and local tumor progression rate of the patients were evaluated.</p><p><b>RESULTS</b>The response rate of treatment (complete ablation at one month on enhanced images) was 100% in these patients. The local tumor progression rates at 1, 3, and 5 years were 0.9%, 2.0%, and 7.1%, respectively, and the 1-, 3-, and 5-year distant metastasis rates were 1.6%, 2.5%, and 7.9%, respectively. The overall survival rates of the patients at 1, 3, and 5 years were 98.4%, 94.8%, 89.5%, respectively, with disease-free survival rates of 98.4%, 93.0%, and 83.1%, respectively. No major complications occurred in these cases, and multivariate analysis showed that the tumor number (P=0.015) and tumor growth patterns (P=0.049) were independent risk factors that adversely affected the long-term outcome after surgery.</p><p><b>CONCLUSION</b>Our data show that microwave ablation is a safe and effective modality for treatment of renal cell carcinoma.</p>

Research of dose-effect relationship parameters of percutaneous microwave ablation for uterine leiomyomas--a quantitative study.

Eighty eight patients with 91 uterine leiomyomas who underwent ultrasound-guided percutaneous microwave ablation (PMWA) treatment were prospectively included in the study in order to study the dose-effect relationship parameters (DERP) of PMWA for uterine leiomyomas and its relationship with T2-weighted MR imaging (T2WI). Based on the signal intensity of T2WI, uterine leiomyomas were classified as hypointense, isointense, and hyperintense. During ablation, leiomyomas were treated with quantitative microwave ablation (QMWA) energy of 50 w × 300 s or 60 w × 300 s. After QMWA, contrast-enhanced ultrasound (CEUS) was performed to evaluate DERP. No matter under 50 w × 300 s or 60 w × 300 s, quantitative microwave ablation volume (QMAV) of hyperintense leiomyoma was smaller than that of hypointense and isointense leiomyoma (P<0.016). For hypointense and isointense leiomyoma, QMAV of 60 w × 300 s was larger than that of 50 w × 300 s (P<0.05). DERPs obtained by T2WI can be used to guide the treatment of uterine leiomyoma by PMWA.

Percutaneous cooled-tip microwave ablation under ultrasound guidance for primary liver cancer: analysis of major complications in 693 patients / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To analyze the major complications of percutaneous cooled-tip microwave ablation for the treatment of primary liver cancer and the possible risk factors of severe complications in a series of 693 patients.</p><p><b>METHODS</b>The clinicopathological data of 693 patients with primary liver cancer who underwent ultrasound-guided percutaneous cooled-tip microwave (MW) ablation in our hospital over the past 5 years were retrospectively analyzed, and the risk factors of severe complications were explored.</p><p><b>RESULTS</b>In a total of 693 patients with 898 primary liver tumors were treated and 1111 MW ablation sessions were performed. The mean diameter of tumors was (2.5 ± 1.2) cm and the range was 0.4 - 10.0 cm. Three deaths occurred in the peri-ablation period, including one case died of multiorgan failure, one case died of pulmonary embolism and one case died of hepatorenal syndrome. Major complications occurred in 27 (3.9%) patients, including 12 pleural effusion requiring thoracentesis (1.7%), 10 tumor seeding (1.4%), 3 liver abscess and empyema (0.4%), 1 hemorrhage requiring arterial embolization (0.1%), and 1 bile duct injury (0.1%). The Chi-square test results showed that the diameter of tumors, number of MW ablation sessions and histological type of tumor were significantly associated with the major complications rate (P < 0.05). The multiple variables 1ogistic regression analysis showed that only type of tumors was associated with the major complication rate (P < 0.05).</p><p><b>CONCLUSIONS</b>Results of this study confirm that cooled-tip MW ablation is a relatively low-risk and effective minimally invasive procedure for the treatment of primary liver cancer. Proper direction for the treatment of cholangiocarcinoma (ICC) patients as well as fewer ablated tumor numbers during one hospital stay may help minimize the major complication rate in patients with primary liver cancer treated by ultrasound-guided percutaneous cooled-tip microwave ablation.</p>

Feasible temperature of percutaneous microwave ablation of dog liver abutting the bowel.

PURPOSE: This study used a dog model to determine the optimal temperature of percutaneous microwave ablation that causes complete necrosis of liver but not the adjacent bowel, supporting the use of this method to specifically and effectively treat liver tumour abutting the bowel. MATERIALS AND METHODS: Ultrasound-guided percutaneous microwave ablation of liver abutting the bowel was performed on healthy adult dogs. Temperature of the ablation margin was monitored and controlled through inserted thermal monitoring needles. Dogs were divided into three groups and received microwave ablation at 75-95°C, 65-75°C, or 55-65°C. Imaging and histological examination were used to evaluate the damage of the bowel adjacent to the ablated liver. RESULTS: Within one hour of treatment, the bowel adjacent to the ablated liver was seriously burned in the group receiving 75-95°C microwave ablation. Inflammation and congestion were found in the submucosa of the bowel in the group receiving 65-75°C microwave ablation. Minor inflammation was found in the mucosa of the bowel in the group receiving 55-65°C microwave ablation. Moreover, in the group receiving 55-65°C microwave ablation, ablated liver areas were covered with omenta, and histological examination revealed inflammatory reaction of the omenta 28 days after ablation. CONCLUSIONS: Microwave ablation at 55-65°C for 6 min is preferred for ablation of liver tissue abutting the bowel in dogs. These findings may provide some valuable reference for percutaneous microwave ablation of human liver tumour adjacent to the bowel.

Clinical evaluation of ultrasound-guided percutaneous microwave ablation of hepatocellular carcinoma adjacent to the gastrointestinal tract / 中华肝脏病杂志

The purpose of the study was to prospectively evaluate safety and assisted with ethanol injection for hepatocellular carcinoma abutting gastrointestinal tract. 263 patients with 319 hepatic tumors that underwent percutaneous microwave ablation with curative intention were included. 101 lesions located less than 5 mm from gastrointestinal tract were in gastrointestinal group. 218 lesions located more than 5 mm from hepatic surface, gastrointestinal tract and first or second branch of hepatic vessels were in control group. The temperature of marginal ablation tissue proximal to gastrointestinal tract was monitored and controlled to fluctuating between 45 degrees C and 59 degrees C for more than 10 min for tumors in the gastrointestinal group. Ethanol (1-21 ml) was injected into marginal tissue in 62 of 101 lesions of the G1 group. 96 of 101 tumors (95.0%) in the gastrointestinal group and 208 of 218 tumors (95.4%) in the control group achieved complete ablation (P = 0.89). Local tumor progression for all the tumors were in the first year and the 6-,12- month local tumor progression rate in the gastrointestinal group and the control group were 6.9%, 11.9% and 7.3%, 8.3%, respectively (P = 0.21). There were neither immediate nor periprocedural complications in both groups. There was no delayed complication of gastrointestinal and bile ducts injury. Tumor seeding happened in one (1.1%) of the gastrointestinal group and three (1.8%) of the control group (P = 0.92). Under strict temperature monitoring, microwave ablation assisted with ethanol injection is safe and achieves a high complete ablation rate for hepatocellular carcinoma adjacent to gastrointestinal tract.